Apparatus And Methods For Managing Communication System Resources

ABSTRACT

Apparatus and methods for managing communication system resources are disclosed. Based on status information received from a resource itself or from other sources, an operational status of a maintenance resource to perform a predetermined maintenance operation on a target communication system resource, for example, may be determined. Access to use resources in performing operations may also be controlled. Resource access is granted or denied based on an availability status of a resource. Other parameters such as relative priorities of a new request to use a resource and a current operation for which access to use the resource was previously granted may also be used in determining whether to grant access to use a resource. A resource may be reclaimed for a higher priority operation for instance. Redundant or alternate resources may also be identified where a resource is not operational or otherwise not available.

FIELD OF THE INVENTION

This invention relates generally to communications and, in particular,to managing communication system resources.

BACKGROUND

Maintenance of communication lines, such as Metallic Test Access (MTA)testing for instance, commonly involves using external test headslocated near communication equipment to be tested. Once a user eithermanually verifies, or simply assumes, that required testing resourcesare present and operational, test functions can be attempted using anexternal test head.

With distributed equipment architectures such as remote DigitalSubscriber Line (DSL) Access Multiplexers (DSLAMs) that are deployed toextend the reach of DSL service from a Central Office (CO), it tends tobe more difficult to verify whether resources such as external cablesconnecting distributed equipment shelves and internal relays that switchinternal test buses are operational and available when needed. Whereswitched test paths are provided between distributed equipment, atesting system becomes even more complex, presenting another challengefor testing management.

Further complicating the goal of testing management is the fact thatresources required to perform a test may involve multiple electroniccircuit cards that can be put into and taken out of service as a resultof being assigned to other tests, communication equipment servicing, orfailures.

Similar challenges may also affect other types of operations thantesting, and other types of resources than those used for testingcommunication systems.

Thus, there remains a need for improved techniques for managingcommunication system resources.

SUMMARY OF THE INVENTION

In accordance with an embodiment of the present invention, the status ofvarious resources, including their configurations, are maintained inorder to request and reserve available resources for performingoperations such as maintenance operations.

Some embodiments of the invention provide a resource manager thatmanages the use of resources within distributed communication equipmentand determines the availability of the resources to perform operations.

According to one aspect of the invention, an apparatus includes aninterface and a resource monitor operatively coupled to the interface.The interface enables transfer of status information associated with amaintenance resource, the maintenance resource being for use inperforming a maintenance operation on a target communication systemresource, and the resource monitor is operable to determine, based onstatus information received through the interface, an operational statusof the maintenance resource to perform a predetermined maintenanceoperation.

The interface may enable transfer of status information associated witha plurality of maintenance resources including the maintenance resource,in which case the resource monitor may be operable to determine a statusof each maintenance resource of the plurality of maintenance resourcesto perform the predetermined maintenance operation.

The apparatus may also include a memory operatively coupled to theresource monitor. The resource monitor is further operable to store inthe memory an indication of the determined operational status of themaintenance resource.

If the target resource comprises a communication line over whichcommunications are supported by communication equipment, which includesthe maintenance resource, the interface may be operatively coupled to acommunication device that exchanges communication signals with thecommunication equipment. The status information may then be exchangedwith the remote communication equipment in the communication signalsaccording to an in-band signalling scheme.

The apparatus may be deployed, for example, in communication equipmentthat also includes the maintenance resource.

Where the communication equipment has a distributed architecture andcomprises a plurality of equipment shelves, which support communicationson respective communication lines and include respective maintenanceresources for use in performing maintenance operations on thecommunication lines as target resources, one equipment shelf of theplurality of equipment shelves may include the interface and theresource monitor. In this case, the interface enables transfer of statusinformation between the resource monitor and each maintenance resourceof the one equipment shelf and between the resource monitor and eachmaintenance resource of each other equipment shelf of the plurality ofequipment shelves. The resource monitor is then operable to determine anoperational status of each maintenance resource of each equipment shelfof the plurality of equipment shelves.

Each equipment shelf of the plurality of equipment shelves may includean internal maintenance path, and respective external connectionsbetween the internal maintenance paths may be provided. At least oneequipment shelf of the plurality of equipment shelves may include a testunit. The maintenance resources for which an operational status isdetermined may include any or all of each internal maintenance path,each test unit of the at least one equipment shelf, and each respectiveexternal connection between the internal maintenance paths.

The apparatus may also include an access controller operatively coupledto the resource monitor and operable to control access to use themaintenance resource for performing a maintenance operation.

A resource client interface may also be operatively coupled to theresource monitor to enable the resource monitor to exchange informationwith a resource client that is operable to use the maintenance resourceto perform a maintenance operation. The resource monitor is operable toreceive a maintenance operation request from the resource client throughthe resource client interface and to return to the resource clientthrough the resource client interface, in response to the maintenanceoperation request, an indication of the determined operational status ofthe maintenance resource to perform the requested maintenance operation.

In some embodiments, the resource client interface is operativelycoupled to the access controller and enables the access controller toexchange maintenance operation information with a resource client. Theaccess controller is operable to receive a maintenance operation requestfrom the resource client through the resource client interface, and toreturn to the resource client through the resource client interface aresponse to the request indicating whether access to use the maintenanceresource is granted or denied.

According to another aspect of the invention, an apparatus includes aresource client interface for enabling exchange of operation informationwith a resource client, the resource client being operable to perform anoperation using a communication system resource, and an accesscontroller operatively coupled to the resource client interface andoperable to determine an availability status of the resource and tocontrol access to the resource by the resource client based on thedetermined availability status.

The operation may be a maintenance operation to be performed on a targetcommunication system resource, in which case the resource comprises amaintenance resource. The target resource may be a communication lineover which communications are supported by communication equipment, thecommunication equipment comprising a plurality of maintenance resourcesincluding the maintenance resource. In this case, the access controlleris operable to determine an availability status of, and to controlaccess to, each maintenance resource of the plurality of maintenanceresources.

The access controller may be operable to receive from the resourceclient through the resource client interface a request for access to usethe resource to perform an operation, and to return to the resourceclient through the resource client interface a response to the requestindicating whether access to use the resource is granted or denied.

In some embodiments, the access controller is further operable, whereaccess to use the resource is denied, to determine whether an alternateresource is available, and to grant access to use the alternate resourcewhere an alternate resource is available.

The access controller may also be operable to update the availabilitystatus of the resource where access to use the resource is granted.

The access controller may determine a priority of the request, anddetermine whether access to use the resource should be granted or deniedbased on the availability status of the resource and the determinedpriority of the request.

A current operation for which access to use the resource was previouslygranted may be halted by the access controller, which may also grantaccess for the resource client to use the resource in response to therequest where the request has a higher priority than the currentoperation.

The access controller may receive from the resource client through theresource client interface an indication that the operation for whichaccess was granted to use the resource has completed, and update theavailability status of the resource in response to receiving theindication.

The apparatus may also include a memory, operatively coupled to theaccess controller, for storing a record associated with the resource,the record comprising an indication of the availability status of theresource. In this case, the access controller may be operable todetermine the availability status of the resource by accessing therecord in the memory.

A machine-implemented method of managing a communication system resourcefor use in performing an operation is also provided, and includesreceiving a request for access to use the resource in performing anoperation, determining an availability status of the resource, anddetermining, based on the determined availability status, whether togrant or deny access to use the resource in response to the request.

The method may also include determining a priority of the request, inwhich case determining whether to grant or deny access to use theresource may involve determining whether to grant or deny access to usethe resource based on the determined availability status of the resourceand the determined priority of the request.

If a current operation for which access to use the resource waspreviously granted is in progress, the method may also includedetermining a priority of the current operation and, where the requesthas a higher priority than the current operation, halting the currentoperation and granting access to use the resource in response to therequest.

Receiving a request for access to use the resource may involve receivinga request from a resource client. The method may then also involve,where access to use the resource is granted in response to the request,receiving from the resource client an indication that the operation hascompleted, and updating the availability status of the resource.

If access to use the resource is denied, the method may also includedetermining whether an alternate resource is available, and grantingaccess to the alternate resource where an alternate resource isavailable.

The method may also include using the resource to perform the operationwhere access to the resource is granted.

Another aspect of the invention provides a machine-readable mediumstoring a data structure. The data structure includes an identifier of amaintenance resource, the maintenance resource being for use inperforming a maintenance operation on a target communication systemresource, and an indication of an operational status of the maintenanceresource to perform a predetermined maintenance operation.

The data structure may also include an indication of an availabilitystatus of the maintenance resource.

Other aspects and features of embodiments of the present invention willbecome apparent to those ordinarily skilled in the art upon review ofthe following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of embodiments of the invention will now be described ingreater detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of a communication system.

FIG. 2 is a block diagram of a communication system resource managementapparatus.

FIG. 3 is a block diagram of a system for managing resources in acommunication system.

FIG. 4 is a block diagram of communication equipment.

FIG. 5 is a block diagram of a distributed communication equipmentarchitecture.

FIG. 6 is a block diagram of another distributed communication equipmentarchitecture.

FIG. 7 is a flow diagram of a communication system resource managementmethod.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 is a block diagram of a communication system 10, in whichembodiments of the invention could be implemented. The communicationsystem 10 includes multiple Customer Premises Equipment (CPE)installations 12/14, 13/15, network elements 16, 17, and a communicationnetwork 18. Although only four CPEs 12/14, 13/15 and two networkelements 16, 17 have been shown in FIG. 1 to avoid overly complicatingthe drawing, many more CPEs and network elements may be connected to thecommunication network 18. It should therefore be appreciated that thesystem of FIG. 1, as well as the contents of the other drawings, areintended solely for illustrative purposes, and that the presentinvention is in no way limited to the particular example embodimentsexplicitly shown in the drawings and described herein.

The CPEs 12/14, 13/15 represent communication equipment, illustrativelyend user communication devices, configured to receive and/or transmitcommunication signals. Although shown as being directly connected to thenetwork elements 16, 17, it will be apparent that CPEs 12/14, 13/15 maycommunicate with the network elements 16, 17 through other intermediatecomponents (not shown). In one embodiment, the CPE connections are localtwisted pair loops used for DSL communications.

Switches and routers are illustrative of the types of communicationequipment represented by the network elements 16, 17. For example, wherethe CPE connections are DSL connections, the network elements 16, 17 maybe DSLAMs.

The communication network 18, in addition to the network elements 16,17, may also include other network elements which route communicationsignals through the communication network 18.

Many different types of end user, intermediate, and networkcommunication equipment, as well as the operation thereof, will beapparent to those skilled in the art. In general, the network elements16, 17 transfer communication signals between the communication network18 and the CPEs 12/14, 13/15. According to one particular exampleimplementation, the network elements 16, 17 communicate with otherequipment in the communication network 18 through Gigabit-Ethernet(Gig-E) communication links, and communicate with the CPEs 12/14, 13/15through DSL. However, embodiments of the invention are not limited toany particular types of communication equipment, transfer mechanisms, orprotocols. The architectures and techniques disclosed herein may be usedin conjunction with other than Ethernet and DSL communications.

As noted above, it may be desirable to distribute, rather thancentralize, communication equipment. Communications over DSL, forinstance, can be improved by locating communication network accessequipment such as DSLAMs as close as possible to CPEs. Distributedsystems, however, can present challenges in respect of managingmaintenance operations.

FIG. 2 is a block diagram of a communication system resource managementapparatus. The apparatus 20 includes a resource database 22, a resourcemanager 24 operatively coupled to the resource database, one or moreresource clients 36 operatively coupled to the resource manager, and oneor more resources 34 operatively coupled to the resource manager and tothe resource client(s). The resource manager 24 includes a resourcemonitor 26 operatively coupled to the resource database 22, a userinterface 30 operatively coupled to the resource monitor, an accesscontroller 28 operatively coupled to the resource monitor and to theresource database, one or more resource client interface(s) 38operatively coupled to the access controller, and one or more resourceinterface(s) 32 operatively coupled to the resource monitor.

The apparatus 20 represents an example of one possible implementation ofan embodiment of the invention. The invention is in no way limited tothe specific example shown in FIG. 2. For example, the functions of theresource monitor 26 and the access controller 28 could be supported by asingle functional element in other embodiments. Thus, more generally,embodiments of the invention may have fewer, further, or differentcomponents with similar or different interconnections than shown in FIG.2 and the other drawings.

The types of connections through which the components of FIG. 2 areoperatively coupled may, to at least some extent, beimplementation-dependent. Communication equipment components often usevarious types of physical connectors and wired connections. In the caseof cooperating software functions, for example, an operative couplingmay be through variables or registers, and thus be a form of logicalcoupling rather than a physical coupling.

The resource database 22 includes resource data records stored in amemory, such as a solid state memory device or a memory device thatoperates in conjunction with a movable or removable storage medium.

Any or all of the other components of the apparatus 20, however, may beimplemented in hardware, software, firmware, or combinations thereof.Electronic devices that may be suitable for this purpose include, amongothers, microprocessors, microcontrollers, Programmable Logic Devices(PLDs), Field Programmable Gate Arrays (FPGAs), Application SpecificIntegrated Circuits (ASICs), and other types of “intelligent” integratedcircuits. The apparatus 20 is therefore described herein primarily interms of its function. Based on the functional description, a personskilled in the art will be enabled to implement the apparatus 20 in anyof various ways.

In operation, a resource interface 32 enables the apparatus 20, and inparticular the resource monitor 26, to obtain status informationassociated with the resource(s) 34, which may be located in the samecommunication equipment shelf as the resource manager 24 or in adifferent equipment shelf in a distributed architecture, for example. Insome embodiments, the resource manager 24 is deployed in one equipmentshelf in a distributed equipment architecture and both one or more localresource interfaces and one or more remote resource interfaces are alsoprovided in that equipment shelf. The resource monitor 26 is therebyenabled to exchange status information with resources in the same shelfthrough the local resource interface(s) and with resources in othershelves of the distributed equipment through the remote resourceinterface(s) and compatible, or identical, resource interfaces in theother shelves.

Those skilled in the art will be familiar with many different types ofinterfaces that may be used for this purpose. The specific structure andoperation of a resource interface will be dependent upon the medium andtransfer mechanism that are to be used to exchange resource statusinformation. According to one embodiment, a local resource interface isphysically connected to a local resource through an equipment backplaneor other internal connection, whereas a remote resource interface isoperatively coupled to a local communication device (not shown) thatexchanges communication signals with other communication equipment,illustratively another equipment shelf in which a remote resource islocated. In the case of the remote resource interface, statusinformation may be exchanged with the remote shelf in the communicationsignals, according to an in-band signalling scheme.

For example, the apparatus 20 could be implemented at a host shelf of adistributed DSLAM that exchanges communication signals with a CO andwith expansion shelves of the distributed DSLAM. The status informationmay be exchanged with the DSLAM expansion shelves by remote resourceinterfaces through other components, implemented at the host shelf, thatalso allow the host shelf to exchange communication traffic with theexpansion shelves.

Another possible mechanism through which the resource manager 24 mayreceive or otherwise obtain information associated with the resource(s)34 is represented in FIG. 2 as the user interface 30. Using an operatorconsole or other input system, a user might enter information thatindicates to the resource manager 24 that an external test cable hasbeen installed between two equipment shelves, for instance.

Thus, the resource manager 24 may obtain resource information frommultiple sources through the same or different types of interfaces.

A resource 34 represents a component that can be used by a resourceclient 36 to perform an operation or function. In one embodiment, theresource(s) 34 include maintenance resources such as a test unit andtest connections for performing maintenance operations on one or morecommunication lines.

In the present disclosure, techniques according to embodiments of theinvention are described primarily with reference to maintenanceoperations that are performed on communication lines using maintenanceresources. However, it should be appreciated that the present inventionmay be used to manage other types of resources than maintenanceresources and/or other types of operations than maintenance operationsperformed on communication lines or other target resources. Referencesherein to resources and operations should be interpreted accordingly.

The resource monitor 26 is operable to determine an operational statusof the resource(s) 34 based on the status information it obtains throughthe resource interface(s) 32, the user interface 30, and/or possiblysome other type of interface. Status information may include, forexample, a response to a request or query that is sent to a resource orcommunication equipment in which the resource is deployed. Handling ofsuch queries, and other possible status transfer mechanisms, aredescribed in further detail below.

Operational status of a resource may include various parameters. Theresource monitor 26, for example, may detect the presence of a resource.If a resource is configurable, then the configuration of the resourcemay also be determined by the resource monitor 26. This could beaccomplished through a query and response mechanism or an automaticupdate procedure. As those skilled in the art will appreciate, sometypes of communication equipment allow components to register for changenotices or similar alerts that are generated when new components areinstalled in a system, existing components fail or are removed from asystem, or configuration changes are made. Thus, the resource monitor 26might be registered to receive such notices or alerts through theresource interface(s) 32 so as to discover new components and to detectfailures, removals, and/or configuration changes.

Where the resource manager 24 manages multiple resources 34, theresource monitor 26 determines a status of each of those resources. Thismay involve repeating determination tasks for each resource 34. Someimplementations may support concurrent status determinations for morethan one resource 34. The multiple resources 34 may include resourcesprovided in a communication equipment shelf, for example, in which casethe resource monitor 26 might receive status information for multipleresources, on a per-shelf basis for instance, in the form of a bulkupdate.

The resource database 22 is populated, at least in part, by the resourcemonitor 26. An indication of the determined operational status of the oreach resource 34, which may include current configurations forconfigurable resources, is stored in the resource database 22 by theresource monitor 26. Other information, such as resource identifiers fornew resources 34 discovered by the resource monitor 26, and/oridentifiers of communication equipment shelves for a communicationequipment installation that has a distributed multiple-shelfarchitecture, may also be stored in the resource database 22 by theresource monitor 26.

Information that has already been stored in the resource database 22 maybe modified by the resource monitor 26 in some embodiments. A record inthe resource database 22 may be deleted by the resource monitor 26 whenremoval of a resource 34 is detected, for instance.

As shown, the apparatus 20 also includes an access controller 28, whichcontrols access to the resource(s) 34 for performing operations. Throughthe resource client interface(s) 38, the access controller 28 is enabledto exchange information with the resource client(s) 36, which may usethe resource(s) to perform any of various operations. In one embodiment,the resource manager 24, and specifically the resource clientinterface(s) 38, communicates with the resource client(s) 36 throughSimple Network Management Protocol (SNMP). Interfaces that support SNMP,and other protocols or transfer mechanisms that may be used, will beapparent to those skilled in the art. Multiple resource client interfacetypes may be provided in some embodiments.

A resource client 36 generally represents a system such as a testconsole or a software application that may perform operations using theresource(s) 34, or at least request access to use those resources. Atest system, for example, may have a user console or other form of userinterface through which an operator can enter, select, or otherwisecause a maintenance operation to be performed on a specific targetresource, illustratively a communication line, or multiple targetresources. Although shown in FIG. 2 as a direct connection, a resourceclient 36 may actually access a resource 34 indirectly, through aninternal or external test head, for example.

Availability status of each of the one or more resources 34 monitored bythe resource monitor 26 is determined, and to some extent controlled, bythe access controller 28. When an operation is to be performed by aresource client 36, for example, the resource client may transmit to theaccess controller 28, through a resource client interface 38, a requestfor access to use the resource to perform the operation. This requestmay specify the operation to be performed and a target resource on whichthe operation is to be performed. The access controller 28 thenidentifies the resource(s) required to perform the requested operation.This may involve accessing the resource database 22 directly, and/orsome interaction with the resource monitor 26. Thus, either or both ofthe access controller 28 and the resource monitor 26 may be involved inparsing or otherwise processing an operation request to identify theresources that are needed for that operation.

Operation to resource mappings may be determined in any of various ways.The resource database 22 or another data store (not shown) may storeoperation/resource mapping tables for instance. The required resourcescan then be identified by accessing these mapping tables. Data that isaccessible to the resource manager 24 might also or instead specify theoperations that can be performed for each possible target resource andthe resources that are needed for those operations.

Information relating to physical connections, and more generallycommunication equipment or network topologies, may also be of use inidentifying the resources that are needed to perform an operation. Thistype of information may additionally allow redundant or otherwisealternate resource combinations to be identified, as described infurther detail below.

Other forms of data records may be or become apparent to those skilledin the art. In some embodiments, required resources may be specified inan operation request, allowing the required resources to be identifiedfrom the request itself. It should thus be appreciated that the presentinvention is not restricted to any specific mechanism for identifyingresources that are associated with a specific operation.

According to an aspect of the invention, all resource client(s) 36 thatcan use the managed resource(s) 34 to perform operations will interactwith the resource manager 24 to gain access or permission to use thoseresources. The access controller 28 can then maintain an accurateaccount of the availability status of all monitored resources. As itgrants access to the resource(s) 34 in response to requests, forexample, the access controller 28 may update records in the resourcedatabase 22 to indicate that those resources are “in use” or “reserved”.An availability status indicator might be stored in the resourcedatabase 22 as a flag or data field in resource-specific data records,for instance. The access controller 28 may therefore, in one embodiment,determine the availability status of the resource(s) 34 by accessing theresource database 22.

It should be appreciated that the access controller 28 may determinewhether to allow or deny access to a resource based on other informationthan availability status. Consider an example of a resource failure.When the resource monitor 26 detects the failure, it updates theoperational status of that resource in the resource database 22accordingly. However, the resource monitor 26 may, but might notnecessarily, also update the availability status of that resource. Ifthe failed resource was not in use or reserved for use at the time ofits failure, then the resource database 22 might incorrectly indicatethat the resource is available. In order to avoid a situation in which aresource client 36 is granted access to and tries to use a failedresource 34, the access controller 28 might also consider a resource'soperational status in determining whether access to the resource shouldbe granted.

The above example also illustrates a scenario in which cooperationbetween the resource monitor 26 and the access controller 28 might be inorder. It may be useful for the access controller 28 to be advised of aresource failure so that an operation using that resource can be haltedif it has not yet been completed. The resource client 36 that wasperforming the halted operation could then be notified of the failureand that the operation has been halted.

The access controller 28 may also support different operationpriorities. Priority may be specified in operation information such asan operation request, or determined by the access controller 28 on someother basis, illustratively the source of a request. For example, auser-requested operation to test a customer connection might takeprecedence over a scheduled operation such as the application of asealing or wetting current to a copper line over which data-only DSLcommunications are carried.

Request and/or operation priorities may be tracked by the accesscontroller 28 by recording a priority indicator when access to aresource is granted. Priorities may be used, for example, to selectbetween conflicting requests for access to the same resource(s) 34.Another possible use for request/operation priorities would be todetermine whether a current operation for which access to a resource waspreviously granted should be halted so that access to the resource canbe granted for another operation. A higher-priority operation requestmay pre-empt a lower-priority current operation. To pre-empt a currentoperation, the access controller 28 effectively seizes control ofresource(s), and may notify the resource client 36 that was performingthe current, halted operation that the operation has been halted andthat its access to the resource(s) has been revoked. Access to theseized resource(s) is then granted for the higher-priority operation.

If the resource(s) 34 required to perform a operation are available, asdetermined by the access controller 28 on the basis of availabilitystatus and possibly other parameters such as those described brieflyabove, then the access controller may provide to the requesting resourceclient 36, through the interface(s) 38, a response to the requestindicating that access to the resource(s) is granted. Request responsesin which resource access is granted may include such operationinformation as identifiers of the required resource(s) 34 and/or howthose resources should be configured.

Once resource access is granted, the resource client 36 uses therequired resources. Use of resources by resource clients is described infurther detail below.

At some time after completion of an operation, a resource client 36 mayprovide a completion indication to the access controller 28. The accesscontroller 28 then updates the availability status of any of theresource(s) 34 that were used to perform the operation in the resourcedatabase 22 responsive to the indication.

If the access controller 28 determines that access to a requiredresource should not be granted, where the resource is not available orhas failed for instance, then a response to an operation requestindicates that requested resource access is denied. The requestingresource client 36 may then retry the operation request at a later time,or execute some other type of failure or exception procedure.

Some embodiments of the invention provide another option for handlingunavailable resources. Suppose that two equipment shelves in adistributed communication equipment architecture each have a test unit.The failure of the test unit in one equipment shelf might notnecessarily mean that tests on target resources associated with thatequipment shelf cannot be performed. External cabling may be providedbetween those shelves, allowing the test unit in the other shelf toperform tests on target resources in the shelf having the failed testunit.

The existence of the external test cable may be reflected in theresource database 22 and detected by the access controller 28 or theresource monitor 26 so as to identify an alternate combination ofresources that may be used to perform a requested operation. In anotherscenario, an operation request relates to a series of operations. If notall of the resources required for the series of operations areavailable, then the access controller 28 or the resource monitor 26 maydetermine a partial series of operations that can be performed using anyavailable required and alternate/redundant resources.

A response to an operation request that grants access to use redundantor alternate resources may include substantially the same content as aresponse that grants access to required resources. However, in the caseof granting access to use redundant or alternate resources in responseto a request for access to specific required resources, a requestingresource client 36 might also be advised of the fact that the redundantor alternate resources should be used to perform the operation. Anyrestrictions in terms of a requested series of operations might also beconveyed to a requesting resource client 36 by the access controller 28.

Resource and operation management in accordance with embodiments of theinvention will be further illustrated with reference to FIG. 3, which isa block diagram of a system 40 for managing resources in a communicationsystem. The system 40 includes a user console 42 and a maintenancesystem 44 as examples of resource clients, communication equipment 46operatively coupled to the user console and to the maintenance system,and one or more external test units 48 that are controllable by themaintenance system 44 and operatively coupled to the communicationequipment. The communication equipment 46, which may include one or moreequipment shelves, includes resource clients 52, one or more internaltest units 54 operatively coupled to the resource clients, a resourcemanager 58 operatively coupled to the resource clients and to theinternal test units, and one or more maintenance resources 56operatively coupled to the internal test unit(s), to the resourcemanager, and to the external test unit(s) 48.

As noted above in conjunction with FIG. 2, FIG. 3 represents an exampleof one possible implementation of an embodiment of the invention. Otherembodiments may include fewer, further, or different components withsimilar or different interconnections than shown. The types ofconnections through which the components of FIG. 3 are operativelycoupled may also be implementation-dependent and include logical and/orphysical couplings.

The resource clients 52, the resource manager 58, and the maintenanceresource(s) 56 may be substantially the same as the similarly-labelledcomponents that are shown in FIG. 2 and described above, although in theexample of FIG. 3, embodiments of the invention are described in thecontext of testing or other maintenance operations performed on targetresources using maintenance resources. The invention is in no waylimited to this example, in which the resource(s) 56 includes one ormore maintenance resources.

The user console 42 and the maintenance system 44 are examples of thetypes of devices or systems through which a user or other entity mayperform maintenance operations using the maintenance resource(s) 56.

Through an internal test unit 54, a resource client 52 is able to usethe maintenance resource(s) 56 to perform maintenance operations. Thesemaintenance operations may include various line tests, application ofsealing current, etc. Line tests may include, for example, narrowbandtests such as those specified in the GR-909 industry specification, orthe more full-featured GR-844 tests. Those skilled in the art will befamiliar with the GR-909 and GR-844 industry specifications. Co-pendingand commonly assigned U.S. patent application Ser. No. <Attorney DocketNo. 51236-143>, incorporated in its entirety herein by reference,discloses an example of an internal test unit 54.

Those skilled in the art will be familiar with test heads and otherforms of an external test unit 48, and the manner in which theseexternal test units are controllable by a maintenance system 44.Interactions between such external test units and test resources willalso be well understood.

In the system 40, however, the resource manager 58 monitors theoperational status of the maintenance resource(s) 56 and also controlsaccess to those maintenance resources by the external and internal testunits 48, 54. When a maintenance operation is to be performed, amaintenance operation request is sent through a resource client 52 tothe resource manager 58. If the maintenance resource(s) 56 needed toperform the maintenance operation are operational and are not in use,access to use the required maintenance resource(s) is granted. As notedabove, a currently in-use maintenance resource 56 may be seized orreclaimed, for example, if a new request has a higher priority than acurrent maintenance operation for which access to use the maintenanceresource was previously granted.

A grant/deny access response is returned to a requesting resource client52 by the resource manager 58. If access to use the required maintenanceresource(s) 56, or in some cases redundant or otherwise alternatemaintenance resources, is granted to a requesting resource client 52,then the requesting resource client may itself use the maintenanceresource(s) to perform the maintenance operation. In the case of amaintenance operation request originating with the user console 42, therequesting resource client 52 performs the maintenance operation throughan internal test unit 54. The maintenance system 44 may instead performa maintenance operation by controlling an external text unit 48.Although the maintenance system 44 interacts with the resource manager58 to obtain access to use the maintenance resource(s) 56 to perform amaintenance operation, a resource client 52 need not be involved inactually performing the maintenance operation.

The internal test unit(s) 54 and the maintenance resource(s) 56 areshown separately in FIG. 3 so as to more clearly illustrate interactionsbetween components of the system 40. It should be appreciated, however,that in some embodiments the resource manager 58 monitors, and may alsocontrol access to, the internal test unit(s) 54 in substantially thesame manner as these functions are performed for the maintenanceresource(s) 56. This is represented in FIG. 3 by the connection 59.

FIGS. 4 through 6 show examples of communication equipment inconjunction with which communication system resource managementtechniques according to embodiments of the invention might beimplemented. As above, these examples are provided for illustrativepurposes only, and represent non-limiting embodiments of the inventionin the context of maintenance resources used to perform maintenanceoperations on target resources.

The communication equipment of FIG. 4 includes an equipment shelf 60having an embedded test unit 62, communication devices 64, 68 thatinclude respective modems 66, 70, and communication line interfaces 72,74. The communication line interfaces 72, 74 are switchably coupled tothe test unit 62 through controllable switches 82, 86, 88 and segmentsof an internal maintenance path 84, and are also operatively coupled tothe modems 66, 70.

The communication equipment shelf 60 represents an example of onepossible implementation of an embodiment of the invention incommunication equipment. Other embodiments may include fewer, further,or different components with similar or different interconnections thanshown.

For example, other components that have not been explicitly shown inFIG. 4 may be involved in transferring control information and/orcommunication traffic to the modems 66, 70 and the test unit 62. In aDSLAM, for example, communications with a CO may be enabled by a Gig-Einterface, or multiple interfaces in some embodiments, through whichinformation is exchanged with the modems 66, 70 and the test unit 62.Different types of interfaces for transferring traffic and controlinformation are also contemplated. The invention is in no way limited tomanaging maintenance operations for communication lines supported bycommunication equipment having a structure as shown in FIG. 4, orspecifically to communication lines as the only possible targetresources on which maintenance operation may be performed.

The types of connections through which the components of FIG. 4 areoperatively coupled may, as noted above with reference to FIGS. 2 and 3,be implementation-dependent and include logical and/or physicalcouplings.

The communication devices 64, 68 may be implemented, for example, in DSLline cards for installation in a DSLAM. In this case, the communicationlines to CPEs serviced by the communication devices 64, 68 are DSLlines, and the communication line interfaces 72, 74 may be DSL portsprovided on the DSL line cards or on separate port cards or “appliques”.

A common implementation of the modems 66, 70, DSL modems in thisexample, is in DSL chipsets. More generally, hardware, software,firmware, or combinations thereof may be used to implement the modems66, 70 and possibly other components of the communication devices 64, 68and/or the communication equipment.

The communication line interfaces 72, 74 represent interfaces throughwhich the communication devices 64, 68 exchange communication signalswith CPEs. Where a CPE communication line is a DSL connection, theinterfaces 72, 74 may include physical ports and associated DSL portcircuitry. Other examples of communication line interfaces will beapparent to those skilled in the art.

Line cards and other communication devices may support communicationlines with more than one remote device such as a CPE. A single DSL linecard might support 24, 48, or more ports and customer connections, forexample. It should therefore be appreciated that the techniquesdisclosed herein may be applied to one, or more than one, communicationline.

The test unit 62, as described above with reference to FIG. 3, can beused by a resource client to perform maintenance operations.

The switches 82, 86, 88, illustratively relays, are also controllable bya resource client, through the test unit 62 or another test unit, so asto connect the internal maintenance path 84 to a communication line, ormore specifically to the interface 72, 74 for such a line, on which amaintenance operation is to be performed. Although local control of theswitches 82, 86, 88 may be provided by the test unit 62, the ultimatecontrol of the switches would rest with a resource client, in that theresource client controls the test unit 62.

The switch 82, which has been shown as a single block but may includemultiple switch elements such as a relay matrix, allows the maintenancepath 84 to be coupled to the internal test unit 62 or to another testunit. The other test unit may be an internal test unit of anotherequipment shelf in a distributed communication equipment architecture oran external test unit such as a test head, for example. This providesflexibility in performing maintenance operations, and may also enableredundancy, as described in further detail below.

The test unit 62, the internal maintenance path 84, and the switches 82,86, 88 represent examples of maintenance resources in the communicationequipment shelf 60.

Considering first the monitoring of operational states of the test unit62, the path 84, and the switches 82, 86, 88, any of various monitoringschemes may be provided. As noted above, a resource monitor may sendqueries to the maintenance resources of the communication equipmentshelf 60. In one embodiment, monitoring queries might be directed to thetest unit 62. This monitoring scheme may be suitable, for example, wherethe test unit 62 provides local control of maintenance resources at thecommunication equipment shelf 60 and resource clients interact with thetest unit to perform maintenance operations.

In response to a monitoring query, the test unit 62 returns operationalstatus information, which may include identifiers of each maintenanceresource and a current configuration of each configurable maintenanceresource, for example. In the case of the switches 82, 86, 88, theoperational status information might include an indication of theposition of each switch. The switch position indications may be anindication of whether the local test unit 62 or another test unit iscoupled to the path 84 by the switch 82 and an identifier of thecommunication line or interface 72, 74 to which the path 84 is currentlycoupled by the switches 86, 88, for instance.

According to some embodiments, a single operational status indicationmight apply to multiple maintenance resources. An indication that theinternal maintenance path 84 is currently connected to the communicationline interface 72, for example, may serve as an indication that themaintenance path and other resources associated with that path,including the switches 86, 88, are in working order and configured in acertain way.

The test unit 62 might also provide an indication as to its ownoperational status. This status indication might instead be an impliedindication, in that a response from the test unit 62 may indicate thatthe test unit is in working order whereas the absence of a response to aquery within a response time window may be interpreted as an indicationof some sort of operational problem with the test unit. An explicitindication of operational status of the test unit 62, or respectivestatus indications for test unit sub-components such as testing circuitsand a sealing current generator for instance, are also contemplated.

Some embodiments of the invention may support maintenanceresource-specific queries. A query/response module might be provided foreach monitored maintenance resource, for example.

A query/response mechanism represents one example of a possiblemonitoring scheme. Automatic updates could also or instead be providedas maintenance resource installations, removals, failures and/orconfiguration changes are detected by the test unit 62 or anothercomponent of the communication equipment shelf 60.

Operational status information may be transferred from the communicationequipment shelf 60 to a remote resource monitor using the same transfermechanism as resource manager to equipment transfers. An in-bandsignalling scheme, as described above, is one example of a possibletransfer mechanism. Where the resource monitor is also implemented inthe equipment shelf 60, a local transfer mechanism through an equipmentbackplane, for example, might be used.

Use of maintenance resources at the communication equipment shelf 60 bya resource client may be accomplished by transferring controlinformation from the resource client to at least a subset of themaintenance resources. It should be appreciated that not all maintenanceresources might be controllable. The internal maintenance path 84, forexample, may be considered a maintenance resource but is not itselfcontrollable, whereas the switches 82, 86, 88 are controlled to connectthe maintenance path 84 in a particular way to perform a maintenanceoperation.

Transfer of control information may be accomplished using the sametransfer scheme as for monitoring information, illustratively an in-bandsignalling scheme. As described above in the context of resourcemonitoring, control of maintenance resources may be direct andresource-specific, or indirect, through the test unit 62 or another testunit. Directly controllable maintenance resources would have anassociated control interface through which control information isreceived from a resource client. In an indirect control scheme, aresource client provides control information to the test unit 62, andthe test unit controls maintenance resources to actually performmaintenance operations.

When a resource client has been granted access to use maintenanceresources for applying a sealing current to a particular communicationline, for example, the resource client may send to the test unit 62instructions to apply sealing current to the line. In one embodiment,the instructions indicate that sealing current is to be applied andidentify the communication line or interface to which the sealingcurrent is to be applied, and the test unit 62 controls the switches 82,86, 88 to connect its sealing current generator to the appropriatecommunication line interface 72, 74. A resource client may have moredirect control over maintenance resources in some embodiments, tocontrol the switches 82, 86, 88 to connect the internal maintenance path84 to a communication line interface 72, 74, and then control the testunit 62 to output a sealing current on the maintenance path 84 after thepath has been switched.

In general, it may be useful to consolidate local control of maintenanceresources at the test unit 62, so as to avoid a resource client havingto directly control each maintenance resource involved in performing amaintenance operation.

FIG. 4 illustrates communication equipment that is implemented using asingle equipment shelf. The present invention can also be extended tomanage maintenance operations for multiple shelves of a distributedcommunication equipment architecture. FIG. 5 is a block diagram of onesuch architecture.

For simplicity, internal details of the communication devices 104, 108,124, 140, 152 have not been included in FIG. 5. A resource manager,which might also be provided in one of the shelves in the distributedarchitecture, has similarly not been explicitly shown so as to avoidfurther complicating the drawing.

The communication equipment shelf 92 may be substantially the same asthe communication equipment shelf 60 (FIG. 4), and includes a test unit102, communication devices 104, 108, and a controllable switch unit 110and switches 114, 116 for connecting the test unit, or another test unitcoupled to the switch unit 110 through an internal maintenance pathsegment 111, to the communication line interfaces 106, 109 through aninternal maintenance path segment 112 or to an external connectorthrough a path segment 118.

The communication devices 104, 108 represent communication devices thatare installed in one equipment shelf 92. As described above withreference to FIG. 4, the single test unit 102 may perform maintenanceoperations on any of the communication lines supported by any of thecommunication devices 104, 108 in an equipment shelf.

The distributed architecture shown in FIG. 5 also includes otherequipment shelves 94, 96, 98 in which other communication devices 124,140, 152 have been installed. Examples of distributed architectures inwhich the shelf 92 is a host shelf and the shelves 94, 96, 98 areexpansion shelves have been disclosed in co-pending and commonlyassigned U.S. patent applications Ser. No. 11/264,451, entitled “REMOTECONTROL AND REDUNDANCY FOR DISTRIBUTED COMMUNICATION EQUIPMENT”, andfiled on Nov. 1, 2005, and Ser. No. 11/264,475, entitled “DISTRIBUTEDCOMMUNICATION EQUIPMENT ARCHITECTURES AND TECHNIQUES”, and also filed onNov. 1, 2005, the entire contents of both of which are incorporatedherein by reference.

The communication devices 104, 108, 124, 140, 152 may have asubstantially similar structure, and are identical line cards in someembodiments. Metal test cables or other connections 119, 128, 150, 162may be used to provide an external maintenance path between the testunit 102 and the shelves 94, 96, 98. Paths to each communication linesupported by the communication devices 124, 140, 152 and operativelycoupled to the communication line interfaces 126, 142, 154 may becompleted through internal switched maintenance paths or other types ofconnections represented by the switches 132, 146, 158.

The shelves 92, 94, 96, 98 may be connected serially in a “daisy chain”,as shown, through the connections 119, 128, 150, 162 and thecontrollable switch units 110, 130, 144, 156. These external connectionsand switch units illustrate one possible arrangement for couplingequipment shelves in a distributed communication equipment architecturetogether. Star- or hub-type inter-shelf connections, as well as othertopologies, are also possible.

As described above with reference to FIG. 4, any communication linesupported by communication equipment can be connected to an internalmaintenance path. The internal maintenance path is coupled to a centralaccess point, represented in FIG. 5 by the controllable switch units110, 130, 144, 156. This central access point may be coupled to aninternal test unit 102, 122 in the case of the equipment shelves 92, 98,or to a test unit in another equipment shelf through the maintenancepath segments 111, 136, 141, 151 and the external connections 119, 128,150, 162.

The equipment shelf 98 illustrates an implementation in which multipleshelves in a distributed communication equipment architecture includerespective test units. The equipment shelf 98 is part of the samedistributed communication equipment as the shelves 92, 94, 96, but hasits own test unit 122. The equipment shelf 92 may be a host shelf forother purposes such as transferring communication traffic. However, thetest unit 122 allows multiple maintenance operations to be performed oncommunication lines supported by the communication device(s) 124 and thecommunication line interface(s) 126 while a maintenance operation issimultaneously being performed in one of the equipment shelves 92, 94,96 by the test unit 102. The switch units 110, 130 may thus establishmultiple connections between their terminals or ports. The switch unit130, for example, might be controlled to connect the externalconnections 119, 128 so as to couple the test unit 102 to the equipmentshelf 94, even if a maintenance operation is currently being performedin the equipment shelf 98 by the test unit 122.

Each test unit 102, 122 may independently perform maintenanceoperations. Where the shelves 92, 98 are interconnected as shown at 119,maintenance operations for the shelf 98 may be performed by either itstest unit 122 or the test unit 102.

Thus, in a distributed architecture, one, some, or all equipment shelvesmay include an internal test unit. In the example shown in FIG. 5, thetest unit 102 provides a measure of redundancy protection for the testunit 122 in that maintenance operations for the equipment shelf 98 canbe performed by the test unit 102 if the test unit 122 fails. As notedabove, this type of redundancy or alternate resource arrangement can insome embodiments be determined by an access controller and/or a resourcemonitor.

If a resource client submits a request to perform a maintenanceoperation on a communication line that is operatively coupled to thecommunication line interface 126, but the test unit 122 is notoperational, then an access controller might respond to the maintenanceoperation request with an indication that the maintenance operationshould be performed by controlling the test unit 102 instead of the testunit 122. Depending on whether a local central control model or aresource-specific control model is implemented, the access controllermight also identify, in the response to the request, the switches 110,130, 132 and how those switches should be configured. It should be notedthat whether the resource client directly or indirectly controls theswitches 110, 130, 132, the availability status of the test unit 102, aswell as the switches, would be updated accordingly by the accesscontroller.

More complete redundancy protection, for the test unit 102 for instance,may also be supported where the test unit 122 can be coupled to theinternal maintenance path 112 of the equipment shelf 92. Such aconnection may be made, for example, through the external connections128, 150, 162. Where the external connection 119 supports bidirectionaltransfers or multiple unidirectional cables are installed between theshelves 92, 96, the test unit 122 may be switchably coupled to theinternal maintenance path 112 of the shelf 92 through the switch unit130, the path segment 136, the external connection 119, the path segment118, and the switch unit 110. Monitoring and control functions in afully redundant system may otherwise be substantially as describedabove.

FIG. 6 is a block diagram of another distributed communication equipmentarchitecture. The components shown in FIG. 6 may be substantiallysimilar to the similarly-labelled components shown in FIG. 5 anddescribed above.

In the system of FIG. 6, however, the external connection 128 betweenthe equipment shelves 98, 94 is replaced with a connection to anexternal test unit 164, illustratively a test head. Where the externalconnections 119, 128, 150, 162 implement a unidirectional daisy chain,the test unit 102 may perform maintenance operations for the equipmentshelves 92, 98, the test unit 122 may perform maintenance operations forthe equipment shelf 98, and the external test head 164 may performmaintenance operations for any of the equipment shelves 94, 96, 92, 98.

According to an alternate implementation of the distributed architectureof FIG. 6, the external connection 162 operatively couples themaintenance path segments 111, 134 of the equipment shelves 92, 98, toprovide full redundancy protection for the test units 102, 122.

FIG. 7 is a flow diagram of a communication system resource managementmethod. The method 170 includes monitoring an operational status of oneor more resources at 172. This may involve exchanging information withcommunication equipment that includes the resource(s), as describedabove. When a resource access-related request is received, the methodproceeds in a different manner depending on the type of request.

At 174, a request for access to use the resource(s) for performing anoperation, such as a maintenance operation on a target resource, isreceived. The availability status of the resource(s) is then determinedat 176. Priorities and/or other parameters may also be determined at176.

Based on the determined availability status and possibly otherparameters, a decision is made at 178 as to whether access to theresource(s) should be granted or denied in response to the request. Ifaccess is denied, then an indication to this effect is returned to arequesting resource client at 180.

If access to the resource(s) is to be granted, then a determination isthen made at 182 as to whether the resource(s) need to be reclaimed fromanother resource client or operation. Where a current operation forwhich access to use the resource(s) was previously granted is inprogress, the current operation might be pre-empted. The decision topre-empt a current operation at 182 may involve determining a priorityof the current operation and a priority of the request received at 174.If the request has a higher priority than the current operation, thenthe current operation could be halted. The current access to theresource(s) is denied at 184, illustratively by sending an access denialor reclaim indication to the resource client that is running the currentoperation. Each reclaimed resource is then released at 186 by revisingthe availability status of the reclaimed resource(s) in a resourcedatabase, for example.

Access to the available resource(s), which may include one or morereclaimed resources, is granted at 188, and the availability status ofthe resource(s) is updated at 190. The requesting resource client maythen use the resource(s) to perform the operation.

When an operation completion indication or other form of request torelease one or more resources is received at 192, the resources arereleased at 194 and thus become available for use in another operation.As shown at 190, the availability of the released resource(s) is updatedin a resource database.

It should be appreciated that the method 170 is illustrative of oneembodiment of the invention. Other embodiments may include further,fewer, or different operations performed in a similar or different orderthan shown.

For example, resource monitoring at 172 may be ongoing during accesscontrol tasks, and/or resume once access to use any requestedresource(s) has been granted or denied.

As described above, alternate or redundant resources may be identifiedin the event that access to the resource(s) is denied at 178.

Further variations may be or become apparent to those skilled in theart.

According to embodiments of the invention as disclosed herein, aresource manager is used to oversee the allocation of resources within asystem. Resources may include components on many electronic circuitcards that provide switchable maintenance path functionality to link atest unit to a target resource to be tested, for example. Resources mayalso include a chain configuration that provides multi-shelf maintenancecapabilities. A test unit such as an external or integrated test headrepresents another example of a resource.

A resource manager may monitor the chain configuration and theoperational and availability states of resources as they becomeavailable or unavailable in order to allow or disallow operationrequests, or even cancel operations that are in progress but are nolonger possible. Termination of operations that are impacted by changesin resource availability or configuration changes avoids unpredictableand unreliable results that would be obtained if such operations wereallowed to continue.

As an example, with reference again to FIG. 5, if the internal test unit122 fails in the shelf 98, then using the maintenance path daisy-chainand the internal test unit 102 in the shelf 92, the system is stillcapable of performing maintenance operations in the shelf 98. The systemmay monitor the hardware devices that are functional in a maintenanceoperation request and attempt to achieve the possible best scenario ofmaintenance resource usage by identifying redundant or alternateavailable maintenance resources. In the case of a maintenance resourcebeing unavailable due to a failure, the system updates its informationbase and re-adjusts itself for ongoing and future tests.

As operation requests are granted, resources are reserved for eachoperation, and after its completion, the allocated resources arereleased for use in performing other operations.

A central process to manage resources shared by various processes may beimplemented ensure consistent and reliable results with the addedbenefit of finding potential alternate methods to obtain the sameresults.

The techniques disclosed herein may also be used to manage resources andoperations for distributed equipment architectures, illustrativelydistributed DSLAMs. The IP DSLAM market, for example, is a competitiveand fast growing market, but many IP DSLAMs are not carrier grade.Having integrated and effective resources in an IP DSLAM can beimportant in providing carrier grade service levels. Therefore,techniques that improve IP DSLAM testing and other maintenancecapabilities in a cost effective manner may be of particular value.

What has been described is merely illustrative of the application ofprinciples of embodiments of the invention. Other arrangements andmethods can be implemented by those skilled in the art without departingfrom the scope of the present invention.

For example, the divisions of functions shown in the drawings areillustrative of embodiments of the invention. Further, fewer, ordifferent elements may be used to implement the techniques disclosedherein.

It should also be appreciated that resource monitoring and accesscontrol may embody substantially independent aspects of the invention.Embodiments of the invention may enable resource monitoring, accesscontrol, or both. Where maintenance resource monitoring is providedwithout access control for instance, a resource monitor may receive amaintenance operation request from a resource client and return to theresource client an indication of the operational status of one or moremaintenance resources to perform a maintenance operation on a targetresource, for instance.

Security measures for enforcing access control have not been describedin detail above, but various options for providing this functionalitywill be apparent to those skilled in the art. An authenticationmechanism could be used by an access controller to ensure that aresource client from which an access request is received is authorizedto perform specific operations or to use particular resources orequipment. Actual control of resources might require a valid ticket orcode issued by the access controller. Other security schemes may also orinstead be provided.

In addition, although described primarily in the context of methods andsystems, other implementations of the invention are also contemplated,as instructions or data structures stored on a machine-readable medium,for example.

As described above, data structures may be provided for maintainingresource operational statuses, resource availability statuses, and/ormappings between operations and resources. An operational status datastructure might include a data record, for each monitored resource, thatincludes a resource identifier and an indication of operational statusof the resource to perform a particular maintenance operation forinstance. An availability data structure may be substantially similar,including per-resource data records, each of which identifies a resourceand indicates its availability status. A mapping data structure mightinclude per-resource records, per-operation records, or some otherarrangement of data identifying resources, operations, and includingeither explicit or implicit indications of relationships betweenresources and operations. Resource-operation relationships could beimplicit in record formats, where resources are listed in per-operationrecords or operations are listed in per-resource records for instance.

These data structure examples are provided solely for the purposes ofillustration. Other specific structures or formats are alsocontemplated. For example, a status data structure might includeindications of both operational and availability status. In someembodiments, a single status indication is used for both operational andavailability status. An indicator might indicate that a resource isreserved (i.e., in service but unavailable), operational (i.e., inservice and available), or failed/out of service (i.e., not in serviceand thus unavailable).

Data structures might also or instead be provided for other purposes,for tracking or recording operation priorities for instance.

1. An apparatus comprising: an interface for enabling transfer of statusinformation associated with a maintenance resource, the maintenanceresource being for use in performing a maintenance operation on a targetcommunication system resource; and a resource monitor operativelycoupled to the interface and operable to determine, based on statusinformation received through the interface, an operational status of themaintenance resource to perform a predetermined maintenance operation.2. The apparatus of claim 1, wherein the interface enables transfer ofstatus information associated with a plurality of maintenance resourcesincluding the maintenance resource, and wherein the resource monitor isoperable to determine a status of each maintenance resource of theplurality of maintenance resources to perform the predeterminedmaintenance operation.
 3. The apparatus of claim 1, further comprising:a memory operatively coupled to the resource monitor, wherein theresource monitor is further operable to store in the memory anindication of the determined operational status of the maintenanceresource.
 4. The apparatus of claim 1, wherein the target resourcecomprises a communication line over which communications are supportedby communication equipment, the communication equipment comprising themaintenance resource, wherein the interface is operatively coupled to acommunication device that exchanges communication signals with thecommunication equipment, and wherein the status information is exchangedwith the remote communication equipment in the communication signalsaccording to an in-band signalling scheme.
 5. Communication equipmentcomprising: the apparatus of claim 1; and the maintenance resource. 6.The communication equipment of claim 5, wherein the communicationequipment has a distributed architecture and comprises a plurality ofequipment shelves, the plurality of equipment shelves supportingcommunications on respective communication lines and comprisingrespective maintenance resources for use in performing maintenanceoperations on the communication lines as target resources, one equipmentshelf of the plurality of equipment shelves comprising the interface andthe resource monitor, wherein the interface enables transfer of statusinformation between the resource monitor and each maintenance resourceof the one equipment shelf and between the resource monitor and eachmaintenance resource of each other equipment shelf of the plurality ofequipment shelves, and wherein the resource monitor is operable todetermine an operational status of each maintenance resource of eachequipment shelf of the plurality of equipment shelves.
 7. Thecommunication equipment of claim 6, wherein each equipment shelf of theplurality of equipment shelves comprises an internal maintenance path,wherein at least one equipment shelf of the plurality of equipmentshelves comprises a test unit, wherein the communication equipmentcomprises respective external connections between the internalmaintenance paths, and wherein the maintenance resources for which anoperational status is determined comprise each internal maintenancepath, each test unit of the at least one equipment shelf, and eachrespective external connection between the internal maintenance paths.8. The apparatus of claim 1, further comprising: an access controlleroperatively coupled to the resource monitor and operable to controlaccess to use the maintenance resource for performing a maintenanceoperation.
 9. The apparatus of claim 1, further comprising: a resourceclient interface operatively coupled to the resource monitor, theresource client interface enabling the resource monitor to exchangeinformation with a resource client, the resource client being operableto use the maintenance resource to perform a maintenance operation,wherein the resource monitor is operable to receive a maintenanceoperation request from the resource client through the resource clientinterface and to return to the resource client through the resourceclient interface, in response to the maintenance operation request, anindication of the determined operational status of the maintenanceresource to perform the requested maintenance operation.
 10. Theapparatus of claim 8, further comprising: a resource client interfaceoperatively coupled to the access controller, the resource clientinterface enabling the access controller to exchange maintenanceoperation information with a resource client, the resource client beingoperable to use the maintenance resource to perform a maintenanceoperation, wherein the access controller is operable to receive amaintenance operation request from the resource client through theresource client interface, and to return to the resource client throughthe resource client interface a response to the request indicatingwhether access to use the maintenance resource is granted or denied. 11.An apparatus comprising: a resource client interface for enablingexchange of operation information with a resource client, the resourceclient being operable to perform an operation using a communicationsystem resource; and an access controller operatively coupled to theresource client interface and operable to determine an availabilitystatus of the resource and to control access to the resource by theresource client based on the determined availability status.
 12. Theapparatus of claim 11, wherein the operation comprises a maintenanceoperation to be performed on a target communication system resource,wherein the resource comprises a maintenance resource, wherein thetarget resource comprises a communication line over which communicationsare supported by communication equipment, the communication equipmentcomprising a plurality of maintenance resources including themaintenance resource, and wherein the access controller is operable todetermine an availability status of, and to control access to, eachmaintenance resource of the plurality of maintenance resources.
 13. Theapparatus of claim 11, wherein the access controller is operable toreceive from the resource client through the resource client interface arequest for access to use the resource to perform an operation, and toreturn to the resource client through the resource client interface aresponse to the request indicating whether access to use the resource isgranted or denied.
 14. The apparatus of claim 13, wherein the accesscontroller is further operable, where access to use the resource isdenied, to determine whether an alternate resource is available, and togrant access to use the alternate resource where an alternate resourceis available.
 15. The apparatus of claim 13, wherein the accesscontroller is further operable to update the availability status of theresource where access to use the resource is granted.
 16. The apparatusof claim 13, wherein the access controller is further operable todetermine a priority of the request, and to determine whether access touse the resource should be granted or denied based on the availabilitystatus of the resource and the determined priority of the request. 17.The apparatus of claim 16, wherein the access controller is operable tohalt a current operation for which access to use the resource waspreviously granted, and to grant access for the resource client to usethe resource in response to the request where the request has a higherpriority than the current operation.
 18. The apparatus of claim 13,wherein the access controller is further operable to receive from theresource client through the resource client interface an indication thatthe operation for which access was granted to use the resource hascompleted, and to update the availability status of the resource inresponse to receiving the indication.
 19. The apparatus of claim 11,further comprising: a memory, operatively coupled to the accesscontroller, for storing a record associated with the resource, therecord comprising an indication of the availability status of theresource, wherein the access controller is operable to determine theavailability status of the resource by accessing the record in thememory.
 20. A machine-implemented method of managing a communicationsystem resource for use in performing an operation, the methodcomprising: receiving a request for access to use the resource inperforming an operation; determining an availability status of theresource; and determining, based on the determined availability status,whether to grant or deny access to use the resource in response to therequest.
 21. The method of claim 20, further comprising: determining apriority of the request, wherein determining whether to grant or denyaccess to use the resource comprises determining whether to grant ordeny access to use the resource based on the determined availabilitystatus of the resource and the determined priority of the request. 22.The method of claim 21, further comprising, where a current operationfor which access to use the resource was previously granted is inprogress: determining a priority of the current operation; and where therequest has a higher priority than the current operation, halting thecurrent operation; and granting access to use the resource in responseto the request.
 23. The method of claim 20, wherein receiving a requestfor access to use the resource comprises receiving a request from aresource client, the method further comprising, where access to use theresource is granted in response to the request: receiving from theresource client an indication that the operation has completed; andupdating the availability status of the resource.
 24. The method ofclaim 20, further comprising, where access to use the resource isdenied: determining whether an alternate resource is available; andgranting access to the alternate resource where an alternate resource isavailable.
 25. The method of claim 20, further comprising: using theresource to perform the operation where access to the resource isgranted.
 26. A machine-readable medium storing a data structure, thedata structure comprising: an identifier of a maintenance resource, themaintenance resource being for use in performing a maintenance operationon a target communication system resource; and an indication of anoperational status of the maintenance resource to perform apredetermined maintenance operation.
 27. The medium of claim 26, whereinthe data structure further comprises: an indication of an availabilitystatus of the maintenance resource.